Apolycrystalline solid: (a) is amorphous (c) is usually anisotropic (b) contains grain boundaries (d) none of these 2. the atomic diameter of an fcc crystal (lattice parameter a) is a2 (c) (b) a2 (d) (1 10) 3. draw the plane whose miller indices are 4. using bohr model of the hydrogen atom, find the largest wavelength of emitted photon when the electron of the hydrogen atom rehurns to its 3 excited state